1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/* Copyright (C) 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Philip Blundell <philb@gnu.org>
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <features.h>
#include <bits/arm_asm.h>
#include <bits/arm_bx.h>
.text
.global memset
.type memset,%function
.align 4
#if defined(THUMB1_ONLY)
.thumb_func
memset:
mov ip, r0
cmp r2, #8 @ at least 8 bytes to do?
bcc 2f
lsl r3, r1, #8
orr r1, r3
lsl r3, r1, #16
orr r1, r3
mov r3, #3
1: @ Fill up to the first word boundary
tst r0, r3
beq 1f
strb r1, [r0]
add r0, r0, #1
sub r2, r2, #1
b 1b
1: @ Fill aligned words
str r1, [r0]
add r0, r0, #4
sub r2, r2, #4
cmp r2, #4
bcs 1b
2: @ Fill the remaining bytes
cmp r2, #0
beq 2f
1:
strb r1, [r0]
add r0, r0, #1
sub r2, r2, #1
bne 1b
2:
mov r0, ip
bx lr
#else
memset:
mov a4, a1
cmp a3, $8 @ at least 8 bytes to do?
blt 2f
orr a2, a2, a2, lsl $8
orr a2, a2, a2, lsl $16
1:
tst a4, $3 @ aligned yet?
#if defined(__thumb2__)
itt ne
strbne a2, [a4], $1
subne a3, a3, $1
#else
strneb a2, [a4], $1
subne a3, a3, $1
#endif
bne 1b
mov ip, a2
1:
cmp a3, $8 @ 8 bytes still to do?
blt 2f
stmia a4!, {a2, ip}
sub a3, a3, $8
cmp a3, $8 @ 8 bytes still to do?
blt 2f
stmia a4!, {a2, ip}
sub a3, a3, $8
cmp a3, $8 @ 8 bytes still to do?
blt 2f
stmia a4!, {a2, ip}
sub a3, a3, $8
cmp a3, $8 @ 8 bytes still to do?
#if defined(__thumb2__)
itt ge
stmiage a4!, {a2, ip}
subge a3, a3, $8
#else
stmgeia a4!, {a2, ip}
subge a3, a3, $8
#endif
bge 1b
2:
movs a3, a3 @ anything left?
IT(t, eq)
BXC(eq, lr) @ nope
#if defined (__thumb2__)
1:
strb a2, [a4], #1
subs a3, a3, #1
bne 1b
bx lr
#else
rsb a3, a3, $7
add pc, pc, a3, lsl $2
mov r0, r0
strb a2, [a4], $1
strb a2, [a4], $1
strb a2, [a4], $1
strb a2, [a4], $1
strb a2, [a4], $1
strb a2, [a4], $1
strb a2, [a4], $1
BX(lr)
#endif
#endif
.size memset,.-memset
libc_hidden_def(memset)
|
